class Acast{
	int a=1;
}
class Bcast extends Acast{
	int b=2;
}
class Ccast extends Bcast{
	int c=3;
}

class testcasting{
	public static void main(String[] args){
		Acast refA;
		refA = new Ccast();
		System.out.println("refA.a의 값은 " + refA.a);
	}
}